Patents by Inventor Masaakira Umehara

Masaakira Umehara has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5196250
    Abstract: An optical information recording medium is composed of a substrate and a recording layer which includes a diarylpolyene compound of formula (I): ##STR1## wherein A.sup.1 and A.sup.2 each independently represent an aryl group which may have a substituent; R.sup.1 and R.sup.2 each represent hydrogen, a halogen or an alkyl group having 1 to 4 carbon atoms; and n is an integer of 2 or more.
    Type: Grant
    Filed: July 18, 1991
    Date of Patent: March 23, 1993
    Assignee: Ricoh Company, Ltd.
    Inventors: Michiharu Abe, Masaakira Umehara
  • Patent number: 5002812
    Abstract: An optical information recording medium comprising a substrate; a recording layer comprising as the main component an organic dye component, formed on the substrate, which recording layer has a maximum peak in the spectroscopic reflectance thereof near the wavelength of the information recording and reproduction light, and has a thickness at which the spectroscopic reflectance thereof is maximized at the wavelength of the information recording and reproduction light, and an optical information recording method, and a system for recording and/or reproducing information using this recording medium are disclosed.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: March 26, 1991
    Assignee: Ricoh Company, Ltd.
    Inventors: Masaakira Umehara, Tsutomu Satoh, Hideaki Ohba, Keiko Ichinose
  • Patent number: 4891305
    Abstract: This invention relate to an optical information recording medium, characterized by having an organic thin film recording layer containing at least one of compounds expressed by the general formula (I), (II), (III) and (IV): ##STR1## (wherein in the above formulas, A, B, D and E represent a substituted or non-substituted aryl group; R.sub.1 to R.sub.8 may be the same or different and represent hydrogen atom, halogen atom or alkyl group; Y represents a divalent residue having atomic groups necessary for forming a five-membered ring or six-membered ring; m, n and l represents 0, 1 or 2; ans X.sup.
    Type: Grant
    Filed: July 7, 1988
    Date of Patent: January 2, 1990
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideaki Oba, Tsutomu Sato, Masaakira Umehara, Yutaka Ueda, Tetsu Yamamuro, Michiharu Abe
  • Patent number: 4767693
    Abstract: This invention provides an optical information recording medium that has, on a substrate, a recording layer containing a cyanine dye represented by the general formula: ##STR1## (wherein, R.sub.1, R.sub.2 and R.sub.3 may be the same or different and each stands for a substituted or unsubstituted alkyl group; X stands for a perhalogenate ion, a toluenesulfonate ion or an alkylsulfate ion; n stands for an integrer of 0 or 1-3; a first halogen atom is present in at least one of each 4, 6 and 7-positions of the indole and indolenine rings; a second halogen atom may be present in each 5-position of said rings; and at lest one group consisting of alkyl, alkoxy, hydroxy, carboxy, allyl and alkylcarbonyl may be present in at least one of each 4, 5, 6 and 7-positions of said rings.) and, if necessary, a transition metal complex or a salt of said complex with a cation.
    Type: Grant
    Filed: October 2, 1987
    Date of Patent: August 30, 1988
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideaki Oba, Yutaka Ueda, Tsutomu Sato, Masaakira Umehara, Michiharu Abe, Hitoshi Funakoshi, Seiko Kobayashi
  • Patent number: 4758499
    Abstract: This invention relates to an optical information recording medium, characterized by having an organic thin film recording layer containing at least one of triaryl methane type coloring matters expressed by the general formula (1), (2) or (3): ##STR1## (wherein, in the above formulas (1) and (2), Ar.sub.1, Ar.sub.2 and Ar.sub.3 may be the same or different and represent a substituted or non-substituted arylene group, at least one pair of optical two nitrogen atoms bonded with said arylene groups being connected by an atomic chain having at least ten carbon atoms in total number in the shortest way; R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6 and R.sub.
    Type: Grant
    Filed: September 5, 1986
    Date of Patent: July 19, 1988
    Assignee: Ricoh Co., Ltd.
    Inventors: Michiharu Abe, Tsutomu Sato, Hideaki Oba, Masaakira Umehara, Yutaka Ueda, Tetsu Yamamuro
  • Patent number: 4714667
    Abstract: The present invention relates to an optical information recording medium comprising a recording layer applied directly on a substrate or applied on a substrate by intervening an underlayer therebetween, and further comprising a protective layer on said recording layer if necessary, characterized in that said recording layer contains at least one of the compounds expressed by the following general formula (I) or (II): ##STR1## (wherein in the above formulas, X.sub.1 to X.sub.3 represent O, S or Se; A.sup.- represents an anion; l, m or n represents 0 or 1; R.sub.4 represents a substituted or non-substituted aryl group or heterocyclic group; R.sub.3, R.sub.5, R.sub.6, R.sub.9, R.sub.10 and R.sub.11 represent hydrogen or an alkyl group; R.sub.1, R.sub.2, R.sub.7, R.sub.8, R.sub.12, and R.sub.13 represent hydrogen or a substituted or non-substituted alkyl, aryl or styryl group; Z.sub.1, Z.sub.3 and Z.sub.
    Type: Grant
    Filed: December 12, 1985
    Date of Patent: December 22, 1987
    Assignee: Ricoh Co., Ltd.
    Inventors: Tsutomu Sato, Masaakira Umehara, Michiharu Abe, Hideaki Oba, Yutaka Ueda
  • Patent number: 4707431
    Abstract: This invention relates to an optical information recording medium comprising a substrate provided at least with an underlayer and a recording layer thereon, said underlayer being prepared by curing a light-curable composition containing a reducing agent, a photo-polymerization initiator and acrylate monomer and/or methacrylate monomer and/or their corresponding oligomer.
    Type: Grant
    Filed: October 25, 1985
    Date of Patent: November 17, 1987
    Assignee: Ricoh Co., Ltd.
    Inventor: Masaakira Umehara
  • Patent number: 4696892
    Abstract: This invention relates to an optical information recording medium, characterized in that on a substrate there is applied a coloring matter film chemically inert to said substrate, said coloring matter film having an extinction coefficient of at least 1.
    Type: Grant
    Filed: February 27, 1985
    Date of Patent: September 29, 1987
    Assignee: Ricoh Co., Ltd.
    Inventors: Michiharu Abe, Masaakira Umehara, Tsutomu Sato, Hideaki Oba, Yutaka Ueda, Makoto Kunikane
  • Patent number: 4656121
    Abstract: This invention relates to an optical information recording medium having an organic thin film recording layer, and optionally having an underlayer and/or protective layer, characterized in that at least one of said recording layer, underlayer and protective layer contains a compound expressed by the general formula (1), ##STR1## wherein R represents hydrogen or a lower alkyl group; X represents acid anion; m represents 0, 1 or 2; and A represents ##STR2## (n being 1 or 2) or ##STR3## (when m is 2); all the aromatic rings optionally having a substituent selected from the group of a lower alkyl group, lower alkoxy group, halogen and hydroxyl group.
    Type: Grant
    Filed: February 6, 1985
    Date of Patent: April 7, 1987
    Assignee: Ricoh Co., Ltd.
    Inventors: Tsutomu Sato, Masaakira Umehara, Michiharu Abe, Hideaki Oba, Yutaka Ueda
  • Patent number: 4614705
    Abstract: This invention relates to an optical information recording medium comprising a substrate, recording layer, under layer and/or under layer having an information track of concavo-convex pattern, characterized in that said under layer on the substrate is formed by curing a light-curable composition by active ray irradiation, and that said light-curable composition contains at least one of photo-polymerizable components selected from the group consisting of (A) difunctional acrylate and/or methacrylate having a functional group comprising a combination of an alkylene glycol with a cycloaliphatic and/or polycycloaliphatic hydrocarbonyl group, (B) difunctional acrylate and/or methacrylate having the general formula, ##STR1## wherein R.sub.1 represents hydrogen or methyl group and n represents an integer of 1 to 10, and (C) difunctional acrylate and/or methacrylate having the general formula, ##STR2## wherein R.sub.1 represents hydrogen or methyl group; R.sub.2 represents an alkylene group of C.sub.2 to C.sub.
    Type: Grant
    Filed: February 7, 1985
    Date of Patent: September 30, 1986
    Assignee: Ricoh Co., Ltd.
    Inventor: Masaakira Umehara
  • Patent number: 4477555
    Abstract: An optical information recording medium comprising a substrate and a recording layer superimposed on said substrate, said recording layer comprising a reflective layer in which metal particles with a particle diameter of 1500.ANG. or less have been distributed closely and a light absorptive layer in which metal compounds and a very small amount of metal particles with a particle diameter of 200-2000.ANG. have been dispersed unformly or substantially uniformly in the volume ratio of 1-30% in a resin.
    Type: Grant
    Filed: July 28, 1982
    Date of Patent: October 16, 1984
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideaki Oba, Makoto Kunikane, Masaakira Umehara, Kiyoshi Tanikawa, Michiharu Abe
  • Patent number: 4465767
    Abstract: An optical information recording medium comprising a substrate and a recording layer superimposed on said substrate, said recording layer being comprised of a reflective layer which contains metal particles having a particle diameter of 1500 .ANG. or less and in which said metal particles have been distributed closely and a light absorptive layer containing a coloring matter.
    Type: Grant
    Filed: September 27, 1982
    Date of Patent: August 14, 1984
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideaki Oba, Masaakira Umehara
  • Patent number: 4460665
    Abstract: An optical information recording medium comprises a transparent or opaque substrate and a cyanine coloring matter-containing thin coloring matter layer formed on said substrate. This recording material is adapted for laser beam reading and writing.
    Type: Grant
    Filed: December 22, 1982
    Date of Patent: July 17, 1984
    Assignee: Ricoh Co., Ltd.
    Inventors: Makoto Kunikane, Michiharu Abe, Masaakira Umehara
  • Patent number: 4332884
    Abstract: A photo-sensitive and heat-sensitive composition consisting essentially of (a) a photooxidant, (b) a color-generator generating color when oxidized, (c) an acid promoting said color generation, (d) a cobalt (III) complex, (e) a photoreductant, (f) a hydrogen donator and (g) a chelating agent consisting of a dioxime compound having the general formula: ##STR1## (where n is an integer of 0 to 3, and R.sub.1 and R.sub.2 can each represent an alkyl, aryl or aralkyl group), and a recording element using the same.
    Type: Grant
    Filed: November 3, 1980
    Date of Patent: June 1, 1982
    Assignee: Ricoh Co., Ltd.
    Inventors: Koji Uji-Ie, Masaakira Umehara, Kiyoshi Taniguchi, Makoto Kunikane
  • Patent number: 4315068
    Abstract: A photo-sensitive and heat-sensitive composition consisting essentially of (a) a photooxidant, (b) a color-generator generating color when oxidized, (c) an acid promoting said color generation, (d) a cobalt (III) ammine and/or amine complex, (e) a photoreductant, (f) a hydrogen donator, (g) at least one kind of chelating agent selected from dioxime chelating agents having the general formula (I): ##STR1## (wherein n is an integer of 0 to 3, and R.sub.1 and R.sub.2 can each represent an alkyl, aryl or aralkyl group) and diantipyrylmethane chelating agents having the general formula (II): ##STR2## (wherein R.sub.3, R.sub.4, R.sub.5, R.sub.3 ', R.sub.4 ' and R.sub.5 ' can each represent a hydrogen atom and an alkyl or aryl group, and R.sub.6 and R.sub.7 can each represent a hydrogen atom and an alkyl, substituted or nonsubstituted aryl or aralkyl group), and (h) at least one kind of stabilizer selected from noble metal complexes, organic oxidants and organic acids, and a recording element using the same.
    Type: Grant
    Filed: January 28, 1981
    Date of Patent: February 9, 1982
    Assignee: Ricoh Co., Ltd.
    Inventors: Makoto Kunikane, Masaakira Umehara, Koji Uji-Ie, Kiyoshi Taniguchi
  • Patent number: 4162843
    Abstract: Three primary color toner images are transferred successively onto a copy sheet from three photoconductive drums. The copy sheet is successively moved into engagement with the drums in register with the toner images by an endless belt. Various transfer charging means are provided to electrostatically adhere the copy sheet to the belt and counteract an adverse accumulation of charge on the copy sheet caused by accumulation of toner substance thereon during the three successive transfer operations.
    Type: Grant
    Filed: November 30, 1977
    Date of Patent: July 31, 1979
    Assignee: Ricoh Company, Ltd.
    Inventors: Satoru Inoue, Masaakira Umehara, Kazuo Aramaki, Hideo Inuzuka, Kouji Yamanobe